Predictors of intensive care unit and hospital length of stay in diabetic ketoacidosis

OBJECTIVE: To determine the predictive value for prolonged intensive care unit (ICU) and hospital length of stay (LOS) in patients with diabetic ketoacidosis (DKA) of the Acute Physiology and Chronic Health Evaluation II (APACHE II) score and Logistic Organ Dysfunction System (LODS), and to identify associated characteristics. DESIGN: Prospective cohort, 18-month observation. SUBJECTS AND SETTING: All admissions to a 12-bed, inner-city, university-affiliated hospital, medical ICU from July 1999 to December 2000. MEASUREMENTS: Data for APACHE II and LODS scoring systems were collected within 24 hours of admission. Lengths of ICU and hospital stay were the primary outcomes. Prolonged ICU and hospital LOS were defined as 3 or more and 6 or more days. RESULTS: A total of 584 patients, mean age 49, 56% men, 82% African American were admitted to the ICU. At admission they had (mean +/-SD) APACHE II (18 +/- 10), LODS (5 +/- 4), and predicted mortality of 32% +/- 29%. DKA was the admitting diagnosis in 42 (7.6%) patients; they had lower APACHE II (12 +/- 6), LODS (2 +/- 1), and predicted mortality 5% +/- 5% than the general ICU population (all, P <.001). Hospital mortality in non-DKA patients was 18%; there were no deaths in patients with DKA. Among DKA patients, those with insulin noncompliance had a shorter hospital stay (2.8 +/- 1 d) than those with an underlying illness as the DKA trigger (4.8 +/- 3, P =.02). Between patients with DKA, regardless of the LOS, there were no significant differences in APACHE II, LODS, or predicted mortality. CONCLUSIONS: ICU-admitted patients with DKA are less ill, and have lower disease severity scores, mortality, and shorter length of ICU and hospital stay than non-DKA patients. Disease severity scores are not, but precipitating cause is, predictor associated with prolonged hospital LOS in patients with DKA.